import numpy as np
import cv2

cap = cv2.VideoCapture('test.avi')

while (cap.isOpened()):
    ret, frame = cap.read();

    ret, frame = cap.read()
    gray = cv2.cvtColor(frame,cv2.COLOR_BGR2GRAY)

    cv2.imshow('frame', gray)

    if cv2.waitKey(1) & 0xFF == ord('q'):
        break;
    

cap.release()
cv2.destroyAllWindows()
